As we all know, young players famously develop in a linear pattern and never struggle after successful seasons or stretches of play.
"Easily" in context meant there could easily be a scenario in which he would replace any of those three players. Neighbours could very easily struggle with scoring goals early and lose confidence and find himself down the lineup. Bolduc hasn't really proven anything at the NHL level, and Saad is an aging complimentary player. Should any of these things happen while Holloway succeeds, he could easily find his way into the mix there. It's not a particularly strong or established 2nd line.
His entire handling of the defense since 2019 has been an issue, a long with betting long term on the wrong players.